Woocommerce estimated shipping date, based on stock and shipping method

woocommerce>checkout>review-order.php

	<table class="shop_table mb-4">
		<tfoot>
			<!-- Skipped top part -->
			
			<!-- Stock part -->
			<?php $stock_values = array(); ?>
			<?php $max_stock_period = 0; ?>
			<?php foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) { ?>
				<?php $_product = apply_filters( 'woocommerce_cart_item_product', $cart_item['data'], $cart_item, $cart_item_key ); ?>
				<?php $stock_status = $_product->get_stock_status(); ?>
				<?php array_push($stock_values, $stock_status); ?>
			<?php } ?>
			<?php if ( in_array( 'onbackorder', $stock_values ) ) { ?>
				<?php $max_stock_period = 14; ?>
			<?php } elseif ( in_array( 'instock', $stock_values ) ) { ?>
				<?php $max_stock_period = 3; ?>
			<?php } ?>
			<!-- END Stock part -->

			<!-- Delivery method part -->
			<?php
				$current_shipping_method_arr = WC()->session->get( 'chosen_shipping_methods' );
				$current_shipping_method = $current_shipping_method_arr[0]; ?>
			<?php
				$shipping_days = 0;
				switch ($current_shipping_method) {
					case 'flat_rate:2':
						$shipping_days = 30;
						break;
					case 'flat_rate:16':
						$shipping_days = 14;
						break;
					case 'flat_rate:7':
						$shipping_days = 10;
						break;
					case 'nova_poshta_shipping:20':
						$shipping_days = 3;
						break;
					default:
						$shipping_days = 0;
			} ?>
			<!-- END Delivery method part -->

			<?php $date = date('d.m.y'); ?>
			<?php $estimated_days = $max_stock_period + $shipping_days; ?>
			<?php $estimateddate = date( 'd.m.y', strtotime(" + $estimated_days days") ); ?>
			
			<tr>
				<th>
					<?php _e( 'Estimated shipping date', 'woocommerce' ); ?>:
				</th>
				<td>
					<strong>
						<?php echo $estimateddate; ?>
					</strong>
				</td>
			</tr>

			<tr class="order-total">
				<th><?php _e( 'Total', 'woocommerce' ); ?></th>
				<td><?php wc_cart_totals_order_total_html(); ?></td>
			</tr>

			<?php do_action( 'woocommerce_review_order_after_order_total' ); ?>

		</tfoot>
	</table>